Apparatus for and method of selecting between antennas for wireless communication

Abstract

A communication device comprising at least first and second antennas wherein a quality of communication between the communication device 2 and a further device 20 is assessed when using the at least first and second antennas 8, 10, 12 so as to select one of the at least first and second antennas for further communications between the communication device and the further device.

The invention claimed is: 
     
       1. A near-field communication device, the device comprising:
 a controller coupled to at least first and second antennas and at least one first and second transceivers, said controller configured to: 
 switch a first switch coupled to the at least first and second transceivers and switch a second switch coupled to the at least first and second antennas between their respective states to connect each of the at least first transceiver and second transceivers to each of the at least first and second antennas; 
 assess a quality of near-field communication between the near-field communication device and a further device modulation depth of a response returned by a further device based on at least one transceiver-antenna combination, wherein the at least one transceiver-antenna combination is derived from one or more combinations of the at least first and second transceivers with the at least first and second antennas;
 select one antenna of the at least first and second antennas combination of the at least one transceiver-antenna combination for further communications between the near-field communication device and the further device based on the result of the assessed quality assessment. 
 
 
     
     
       2. The near-field communication device of  claim 1 , wherein the at least one transceiver connects sequentially to the at least first and second antennas. 
     
     
       3. The near-field communication device of  claim 1 ,
 wherein the at least one transceiver comprises a plurality of transceivers with a separate transceiver of the plurality of transceivers connected to each of the at least first and second antennas. 
 
     
     
       4. The near-field communication device of  claim 1 ,
 wherein the at least one transceiver comprises a plurality of transceivers with each transceiver of the plurality of transceivers having a different frequency. 
 
     
     
       5. The near-field communication device of  claim 1 , wherein the selected one antenna is the first antenna of the at least first and second antennas, and wherein the selection of the first antenna is based on a determination that an electromagnetic coupling between the first antenna and a further antenna of the further device is substantially different to an electromagnetic coupling between a second antenna of the at least first and second antennas and the further antenna of the further device. 
     
     
       6. The near-field communication device of  claim 1 , wherein the at least first and second antennas are of a different physical size. 
     
     
       7. The near-field communication device of  claim 1 , wherein the at least first and second antennas are of a different physical shape. 
     
     
       8. The near-field communication device of  claim 1 , wherein the at least first and second antennas are formed on at least one planar substrate. 
     
     
       9. The near-field communication device of  claim 1 , wherein the at least first and second antennas are spatially non-overlapping. 
     
     
       10. A near-field communication method, the method comprising:
 switching a first switch coupled to the at least first and second transceivers and switching a second switch coupled to the at least first and second antennas between their respective states to connect each of the at least first transceiver and second transceivers to each of the at least first and second antennas; 
 assessing a quality of near-field communication between a near-field communication device and a further device modulation depth of a response returned by a further device based on at least one transceiver-antenna combination, wherein the at least one transceiver-antenna combination is derived from one or more combinations of the at least first and second transceivers with the at least first and second antennas; 
 selecting one of at least and first and second antennas in the near-field communication device combination of the at least one transceiver-antenna combination for further communications between the near-field communication device and the further device based on the result of the assessed quality assessment. 
 
     
     
       11. The method of  claim 10 , wherein the assessing further comprises connecting sequentially to the at least first and second antennas. 
     
     
       12. The method of  claim 11 , wherein the connecting further comprises connecting to each of the at least first and second antennas using a different transceiver. 
     
     
       13. The method of  claim 11 , wherein the connecting further comprises connecting to each of the at least first and second antennas using a plurality of transceivers, and wherein each transceiver of the plurality of transceivers has a different frequency. 
     
     
       14. The method of  claim 10 , wherein the selected one antenna is the first antenna of the at least first and second antennas, and wherein the selecting further comprises determining that an electromagnetic coupling between a first antenna of the at least first and second antennas and a further antenna of the further device is substantially different to an electromagnetic coupling between a second antenna of the at least first and second antennas and the further antenna of the further device. 
     
     
       15. A near-field communication device, the device comprising:
 a first transceiver operating at a first carrier frequency and coupled to a first switch and at least one other transceiver operating at another carrier frequency and coupled to the first switch, where the first switch connects the first transceiver to a common node in a first switch first state and connects the at least one other transceiver to the common node in a first switch other state; 
 a first antenna coupled to a second switch and at least one other antenna coupled to the second switch, where the second switch connects the first antenna to the common node in a second switch first state and connects the at least one other antenna to the common node in a second switch other state; 
 a controller coupled to each transceiver and each switch, wherein the controller:
 switches the first switch and the second switch between their respective states to connect each of the first transceiver and the at least one other transceiver to each of the first antenna and the at least one other antenna, 
 assesses a modulation depth of a response returned by the further device based on at least one transceiver-antenna combination, wherein the at least one transceiver-antenna combination is derived from one or more combinations of the first transceiver and the at least one other transceiver with the first antenna and the at least one other antenna, and 
 selects one combination of the at least one transceiver-antenna combination for further communications between the near-field communication device and the further device based on the result of the assessment.